extend README
extend README

* add section for required dependencies
* add section for depends-maven-plugin
* add note for SlingVersionResolver#setVersionFromProject(…)

git-svn-id: 6eed74fe9a15c8da84b9a8d7f2960c0406113ece@1761806 13f79535-47bb-0310-9956-ffa450edef68

anchela/sling,mcdan/sling,labertasch/sling,labertasch/sling,awadheshv/sling,ieb/sling,awadheshv/sling,JEBailey/sling,anchela/sling,ieb/sling,mikibrv/sling,vladbailescu/sling,cleliameneghin/sling,trekawek/sling,headwirecom/sling,mcdan/sling,mikibrv/sling,anchela/sling,trekawek/sling,anchela/sling,tmaret/sling,tmaret/sling,mikibrv/sling,roele/sling,ieb/sling,vladbailescu/sling,ist-dresden/sling,ieb/sling,trekawek/sling,mcdan/sling,ieb/sling,JEBailey/sling,mikibrv/sling,trekawek/sling,cleliameneghin/sling,vladbailescu/sling,mikibrv/sling,labertasch/sling,JEBailey/sling,trekawek/sling,tmaret/sling,mcdan/sling,headwirecom/sling,ist-dresden/sling,mikibrv/sling,awadheshv/sling,tmaret/sling,labertasch/sling,cleliameneghin/sling,awadheshv/sling,trekawek/sling,JEBailey/sling,awadheshv/sling,roele/sling,labertasch/sling,cleliameneghin/sling,anchela/sling,roele/sling,ieb/sling,roele/sling,awadheshv/sling,headwirecom/sling,headwirecom/sling,vladbailescu/sling,roele/sling,tmaret/sling,ist-dresden/sling,headwirecom/sling,vladbailescu/sling,mcdan/sling,mcdan/sling,cleliameneghin/sling,ist-dresden/sling,JEBailey/sling,ist-dresden/sling